gene sequencing will also help track the spread of the variant here. we all want to know how much of a threat omicron poses, but it will be two to three weeks before science gives us those answers. fergus walsh, bbc news. i'm joined now by dr william schaffner, medical director at the national foundation for infectious diseases — he's based in nashville. it's wonderful to have you on the programme, doctor. just listening to my colleague's report there, so little is still known about this variant. there still haven't been thankfully any known to cases of severe illness yet. as i giving you cause for cautious optimism? weill. cause for cautious optimism? well, aenerall , cause for cautious optimism? well, generally, unconsciously _ cause for cautious optimism? -ii generally, unconsciously optimistic, and those repents reinforce my